Conveyor belts of the type described above are often used in air conditioning plants for e.g. quick-freezing or cooking of food products.
Such conveyor belts are usually made up of links which comprise upward extending lateral plate elements and at least two parallel transverse rods connected thereto. The links are interconnected in such a manner that the conveyor belt is turnable vertically and laterally.
The lateral plate elements of the links of the conveyor belt may, however, be designed in various ways. Examples of conveyor belts of the above type having differently designed lateral plate elements are e.g. described in WO87/04136, WO91/04209, EP1714918, U.S. Pat. Nos. 6,237,750 and 7,270,231, the disclosures of which are fully incorporated herein by reference.
Normally each lateral plate element includes an integrally formed outer one-half plate section and an inner one-half plate section. The outer one-half plate section is slightly offset outwardly with respect to the inner one-half plate section thereby enabling the inner one-half plate section on a link to extend over the inside surface of the outer one-half plate section on the adjacent link. During operation, the outer one-half plate section on a link and the inner one-half plate section on an adjacent link overlap and slide together as the belt moves along its path.
The conveyor belt may be arranged to travel in a straight path until it enters a spiral or helical configuration. When aligned in the helical configuration, the lowermost tier of the conveyor belt is supported by a drive system while each of the remaining tiers is supported by an underlying tier. The interface between adjacent tiers is designed to keep the belt supported and laterally aligned.
During use, an upper edge of the link in the underlying tier normally contacts the bottom surfaces of the transverse rods of the links in the overlying tier. The tiers are laterally aligned by resting said upper edge against said transverse rods and by guide tabs arranged on the links of the overlying tier.
As a further development the lateral plate elements are designed so that the upper edge of the lateral plate element in the underlying tier contacts a resting surface of the lateral plate element in the overlying tier, see for example U.S. Pat. Nos. 6,237,750 and 7,270,231. By designing the lateral plate elements to have such a resting surface resting said upper edge of the lateral plate element in the underlying tier against said transverse rods may be avoided. And consequently wear on the transverse rods which may lead to breakage may be avoided.
By designing the lateral plate elements to have such a resting surface it must be safeguarded that the resting surface of a lateral plate element of an overlaying tier does not fall of the upper edge of a lateral plate element in the underlying tier. In other words it must be safeguarded that wedging between a lower and upper lateral plate element in the conveyor belt is prevented. This is typically achieved by guide tabs arranged on the lateral plate elements of the overlying tier.
However, there is still a need for improving the lateral plate element so that it is ensured that the resting surface of a lateral plate element of an overlaying tier does not fall of the upper edge of a lateral plate element in the underlying tier and so that it is ensured that wedging between a lower and upper lateral plate element in the conveyor belt along its helical path is avoided. Consequently, there is a need for an improved lateral plate element.